Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide. Semiconductor devices are manufactured both as single discrete devices and as integrated circuits (ICs), which include a quantity, from a few to millions, of devices manufactured and interconnected on a single semiconductor substrate. A semiconductor package can include one or more metal leadframes, one or more semiconductor die attached to a die pad of the leadframe, bonding wires which electrically connect pads on the die to individual leads of the leadframe, and a hard plastic packaging material, or encapsulant, which covers the other components and forms the exterior of the packaged electronic device. The packaging material, or encapsulant, provides protection from hostile environments.
Power semiconductor devices are discrete devices or integrated circuits intended for high current or high voltage applications. Due to relatively large current conduction, power semiconductor devices heat up during operation. Unfortunately, semiconductors do not perform well at elevated temperatures. Therefore, a power semiconductor device needs to be cooled by removing that heat continuously. Accordingly, a power semiconductor device is typically attached to a platform layer or heat sink to remove the heat caused by operation losses. This heat is subsequently carried outside of the power semiconductor device.
Semiconductor devices, including power semiconductor devices, continue to shrink in physical size and expand in functionality. Unfortunately, leadframe technology has in many instances reached its theoretical limits in terms of lead pitch and density. Consequently, a need has arisen for increased capability in terms of having a greater amount of electrical interconnects than that afforded by leadframe technology.
Organic substrate materials provide a means to increase circuit density over leadframe technology. However, organic substrate materials cannot withstand the high temperatures encountered during processing, such as the high temperature required for fabrication of semiconductor devices, for attachment of a power semiconductor die to a heat sink platform, and the like. Nor can organic substrate materials adequately dissipate the heat generated by a power semiconductor device. Thus, what is needed is a technique for effectively increasing circuit density of a semiconductor device, such as a power semiconductor die, that is able to withstand high processing temperatures and effectively dissipate generated heat.